#define _CRT_SECURE_NO_WARNINGS 1

#pragma once
#include <assert.h>
#include <iostream>
#include <string>
using namespace std;

namespace My
{
	class string
	{
	public:
		typedef char* iterator;
		typedef const char* const_iterator;
		iterator begin()
		{
			return _str;
		}
		iterator end()
		{
			return _str+_size;
		}
		const_iterator begin()const
		{
			return _str;
		}
		const_iterator end()const
		{
			return _str + _size;
		}
		/*string()
			:_str(new char[1]{'\0'})
			,_size(0)
			,_capacity(0)
		{}*/

		string(const char* str="")
		{
			_size = strlen(str);
			_capacity = _size;
			_str = new char[_capacity+1];
			strcpy(_str, str);
		}

		const char* c_str()const
		{
			return _str;
		}

		string(const string& str)
		{
			_str = new char[str._capacity + 1];
			strcpy(_str , str._str);
			_capacity = str._capacity;
			_size = str._size;
		}

		void clear()
		{
			_str[0] = '\0';
			_size = 0;
		}

		string& operator =(const string& s)
		{
			if (&s == this)
			{
				return *this;
			}

			delete[]_str;
			_str = new char[s._capacity + 2];
			strcpy(_str, s._str);
			_capacity = s._capacity;
			_size = s._size;
			return *this;
		}

		~string()
		{
			delete[]_str;
			_str = nullptr;
			_capacity = _size = 0;
		}

		size_t size()const
		{
			return _size;
		}
		size_t capacity()const
		{
			return _capacity;
		}

		char& operator[](size_t pos)
		{
			assert(pos < _size);
			return *(_str + pos);
		}
		const char& operator[](size_t pos)const
		{
			assert(pos < _size);
			return *(_str + pos);
		}
		void reserve(size_t n);
		void push_back(char ch);
		void append(const char* str);
		string& operator +=(char ch);
		string& operator +=(const char* str);

		void insert(size_t pos, char ch);
		void insert(size_t pos, const char* str);
		void erase(size_t pos, size_t len = npos);

		size_t find(char ch, size_t pos = 0);
		size_t find(char* str, size_t pos = 0);

		string substr(size_t pos = 0, size_t len=npos);


	private:
		char* _str;
		size_t _size;
		size_t _capacity;

		static const size_t npos;
	};

	bool operator<(const string& s1, const string& s2);
	bool operator<=(const string& s1, const string& s2);
	bool operator>(const string& s1, const string& s2);
	bool operator>=(const string& s1, const string& s2);
	bool operator==(const string& s1, const string& s2);
	bool operator!=(const string& s1, const string& s2);

	ostream& operator <<(ostream& out,const string& s);
	istream& operator >>(istream& in,string& s);
	
	istream& getline(istream& is, string& str);
}
